This is a phase 1/2, open label study of D-1553 single agent treatment to assess the safety and tolerability, identify the MTD and RP2D, evaluate the PK properties and antitumor activities in subjects with advanced or metastatic NSCLC with KRasG12C mutation

Inclusion Criteria:

• Subject with histologically proven, locally advanced, unresectable and/or metastatic NSCLC for which no standard treatment is available or the subject is refractory to or intolerant of existing standard treatment.
• Subject has KRasG12C mutation in tumor tissue or other biospecimens containing cancer cells or DNA. Historical, local laboratory result (up to 5 years prior to this study) can be used for Phase 1 subjects. Phase 2 subjects must be tested for KRasG12C mutation by a central laboratory.
• Subject has measurable disease according to RECIST, v1.1

Exclusion Criteria:

• Subject with unstable or progressive central nervous system (CNS) metastases.
• Subjects with clinically significant cardiovascular disease
• Subject with interstitial lung disease (ILD) or any active systemic infection including but not limited to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.
• Subject has impaired gastrointestinal (GI) function or GI diseases that may significantly alter the absorption or metabolism of oral medications.
• Subject is pregnant or lactating.